diff --git a/cpdfembed.mli b/cpdfembed.mli
index 08510ec..93ebd46 100644
--- a/cpdfembed.mli
+++ b/cpdfembed.mli
@@ -1,3 +1,5 @@
+(** Embed a TrueType font in a PDF *)
+
 (* Embed a TrueType font for the given set of unicode codepoints in the given
    encoding, adding the fontfiles to the PDF and returning a list of font objects,
    together with a unicode codepoint --> (font number in list, charcode) table *)
@@ -9,13 +11,16 @@ type cpdffont =
 | EmbedInfo of {fontfile : Pdfio.bytes; fontname : string; encoding : Pdftext.encoding}
 | ExistingNamedFont
 
+(** Build a fontpack for a Standard 14 font *)
 val fontpack_of_standardfont : Pdftext.font -> t
 
-(* Returns (charcode, fontnumber, font) *) 
+(** Look up a unicode codepoint in a font page. Returns (charcode, fontnumber, font) *) 
 val get_char : t -> int -> (int * int * Pdftext.font) option
 
+(** Build a fontpack from a TrueType font and list of codepoints, embedding its fonts in the document *)
 val embed_truetype :
   Pdf.t -> fontfile:Pdfio.bytes -> fontname:string -> codepoints:int list ->
   encoding:Pdftext.encoding -> t
 
+(** Collate outputs of [get_char] with like font *)
 val collate_runs : ('a * 'b * 'c) list -> ('a * 'b * 'c) list list
diff --git a/cpdftruetype.mli b/cpdftruetype.mli
index 845fa76..d52fa6a 100644
--- a/cpdftruetype.mli
+++ b/cpdftruetype.mli
@@ -1,6 +1,6 @@
-(* Parse and subset TrueType fonts *)
+(** Parse and subset TrueType fonts *)
 
-(* The type of a single parsed font, including everything needed to build a PDF font. *)
+(** The type of a single parsed font, including everything needed to build a PDF font. *)
 type t =
   {flags : int;
    minx : int;
@@ -22,9 +22,8 @@ type t =
    subset : int list;
    tounicode : (int, string) Hashtbl.t option}
 
-(* Parse the given TrueType font file. It will return one or more fonts. The
+(** Parse the given TrueType font file. It will return one or more fonts. The
    first, a plain Latin font in the given encoding. Others are for the
-   additional characters in the font. For subsetting, or to return a full
-   font-pack, you should supply a subset (a list of unicode codepoints whose
-   corresponding glyphs are required). *)
+   additional characters in the font. You should supply a subset (a list of
+   unicode codepoints whose corresponding glyphs are required). *)
 val parse : subset:int list -> Pdfio.bytes -> Pdftext.encoding -> t list